See pic below. Sensor in ATO reservoir. Sensor attracts bubbles when it fills. Sensor says Open.
What’s the hack / workaround?
Cover it with a bit of PVC pipe to try and prevent ? Rub it down with Vaseline ;-)
The sensor should not be mounted facing down. Aside from the bubble problem you have, when the water level is low, a drip of water can cling to the tip of the sensor to produce a false Closed reading. I bet if you mounted it horizontally the bubbles wouldn’t be an issue.
The OS-1 must be oriented properly. An OS-1 may be mounted horizontally, or may be mounted with the clear pyramid pointing UP. It must not be mounted with the clear pyramid pointing down; if improperly mounted pointing downward, a drop of water clinging to the tip could result in a false indication of water level.